package com.qdxwx.captcha.impl;

import com.qdxwx.captcha.NoiseProducer;
import com.qdxwx.captcha.util.Configurable;

import java.awt.*;
import java.awt.geom.CubicCurve2D;
import java.awt.geom.PathIterator;
import java.awt.geom.Point2D;
import java.awt.image.BufferedImage;
import java.util.Random;

public class DefaultNoise extends Configurable implements NoiseProducer
{
    /**
     * Draws a noise on the image. The noise curve depends on the factor values.
     * Noise won't be visible if all factors have the value > 1.0f
     *
     * @param image
     *            the image to add the noise to
     * @param factorOne
     * @param factorTwo
     * @param factorThree
     * @param factorFour
     */
    public void makeNoise(BufferedImage image, float factorOne,
                          float factorTwo, float factorThree, float factorFour)
    {
        Color color = getConfig().getNoiseColor();

        // image size
        int width = image.getWidth();
        int height = image.getHeight();

        // the points where the line changes the stroke and direction
        Point2D[] pts = null;
        Random rand = new Random();

        // the curve from where the points are taken
        CubicCurve2D cc = new CubicCurve2D.Float(width * factorOne, height
                * rand.nextFloat(), width * factorTwo, height
                * rand.nextFloat(), width * factorThree, height
                * rand.nextFloat(), width * factorFour, height
                * rand.nextFloat());

        // creates an iterator to define the boundary of the flattened curve
        PathIterator pi = cc.getPathIterator(null, 2);
        Point2D[] tmp = new Point2D[200];
        int i = 0;

        // while pi is iterating the curve, adds points to tmp array
        while (!pi.isDone())
        {
            float[] coords = new float[6];
            switch (pi.currentSegment(coords))
            {
                case PathIterator.SEG_MOVETO:
                case PathIterator.SEG_LINETO:
                    tmp[i] = new Point2D.Float(coords[0], coords[1]);
            }
            i++;
            pi.next();
        }

        pts = new Point2D[i];
        System.arraycopy(tmp, 0, pts, 0, i);

        Graphics2D graph = (Graphics2D) image.getGraphics();
        graph.setRenderingHints(new RenderingHints(
                RenderingHints.KEY_ANTIALIASING,
                RenderingHints.VALUE_ANTIALIAS_ON));

        graph.setColor(color);

        // for the maximum 3 point change the stroke and direction
        for (i = 0; i < pts.length - 1; i++)
        {
            if (i < 3)
                graph.setStroke(new BasicStroke(0.9f * (4 - i)));
            graph.drawLine((int) pts[i].getX(), (int) pts[i].getY(),
                    (int) pts[i + 1].getX(), (int) pts[i + 1].getY());
        }

        graph.dispose();
    }
}
